Fire protective system



Oct. 6, 1942. L; M. LEWIS 9 FI-RE. PROTECTIVE SYSTEM F led Dec. 20, 1940 M f g. F I F \S Ju 419:

I9 O 2 Q 23 v I8 (2/ 2! as INVENTOR. l5 w R Y M.LEWIS ATTORNEY l Patented Oct. 6, 1942 I'TED STATES PATENT 'FFI CE FIRE PROTECTIVE SYSTEM Leroy M. Lewis, Rosemont, Pa. Application December 20, 1940, Serial No. 370,926

2 Claims.

This invention has to do with fire protective systems and is concerned primarily with a system of the so-called dry pipe type.

The need for protecting various types of unheated buildings, such' as many factories, warehouses, airplane hangars, and the like, has resulted in the now substantially widespread use of dry pipe protective systems. A dry pipe system may be generally characterized as comprising a water conduit system including a plurality of spray heads, and this system is maintained dry and free from water. The dry pipe conduit system is connected to a source of supply of water under pressure by a control valve which is generally known as a deluge or torrent valve.

For a long time it was the practice to maintain the deluge valve closed by air that is maintained at a required pressure in the pressure chamber of the valve and the dry pipe system communicating therewith. When this arrangement was employed, a fusible unit was operatively associated with each spray head for normally maintaining the same closed. However, when this unit was afiected by heat it would collapse, and cause the spray head to open under the influence of the pressure of air in the system, whereupon the pressure of air in the pressure chamber would be relieved and the deluge valve opened to cause water to flow from the source of supply to the dry pipe system and through the open spray head.

A 'fire protective system following the immediately above outlined principles proved to present certain unsatisfactory features, one of which was the impedance to the flow of water which was offered by the air pressure in the dry pipe system. Because of this, and other undesirable features, attempts have been made to improve these dry pipe systems. One result of such effort is the system disclosed in the copending application of Leroy M. Lewis, Serial No. 354,043, filed August 24, 1940, entitled Fire preventive system.

In the arrangement illustrated and described in the above identified application, the deluge valve is maintained closed by the pressure of air in the pressure chamber, but the pressure chamber is not in communication with the dry pipe system itself, as an auxiliary control system is employed which communicates with the pressure chamber. In the said Lewis application all of the spray heads of the dry pipe system are maintained open, while the spray heads of the auxiliary system are maintained closed by the fusible units which are well-known in this art.

When heat affects one of these fusible units it collapses, and the spray head which it con- 5 trols'opens to relieve pressure from the auxiliary system, and correspondingly in the pressure chamber of the deluge valve to cause the latter to open, whereupon water flows from the source ofsupply into the dry pipe system and emerges from all the open spray heads. This arrangement has proven to be desirable in that it not only provides the spraying at the particular point where the temperature has risen, but at other locations thereabout so as to not only extinguish a fire, but prevents the spreading of the same.

Asa result of these efforts to improve the old type of dry pipe system another arrangement has been proposed, such as set forth in the application of Leroy M. Lewis, Serial No. 353,227, filed August 20, 1940, and entitled Fire preventive system. I In this last mentioned application the arrangement of the dry pipe conduit system with the open spray heads is employed. A deluge valve is also utilized to connect this dry pipe system to the source of water .supply. Pressure of the fluid in the pressure chamber which maintains the deluge valve closed may be relieved by a bypass, which ordinarily is kept closed by a 30 fusible unit. This fusible unit is electrically connected to a plurality of thermostats that are appropriately distributed over the area to be protected.

These thermostats are known in the art as .35 rate of rise or "fixed temperature thermostats, and when the temperature condition about any of the thermostats reaches a danger point the electrical circuit to the fusible unit is closed. As the current flows through the fusible unit it generates heat to cause the latter to collapse,

whereupon the bypass from the pressure chamber is open and the pressure therein relieved to open the deluge valve.

While certain advantages have been attained from the systems of the aforesaid Lewis applications, there is still a highly undesirable factor which is intended to be avoided-by this invention. In many structures, such as airplane hangars and other large drafty buildings, there is grave danger of a fire quickly spreading. This same liability is present. in many buildings where the air might become laden with dust or other inflammable materials. When these highly dangerous conditions are present it is important that 55 the fire protective system be brought into opera ation as quickly as possible, but in each of the above outlined systems there is an undesirable lapse of time from the creation of the dangerous condition in the area to be protected to the time when water commences to emerge from the spray heads, and it is the primary object of this invention to materially reduce this lapse of time so as to render the operation of the fire protective system substantially instantaneous.

In carrying out this object this invention follows the same arrangement of employing a dry pipe water conduit system carrying the plurality of open spray heads, and which dry pipe conduit system is connected to a source of supply of water under pressure by a deluge valve. A deluge valve such as is now well-known in this art is employed, and this valve has a pressure chamber in which air is maintained under pressure to keep the valve closed.

In accordance with this invention a header communicates with the pressure chamber of the valve, and appropriate means is provided for maintaining air in the header and pressure chamber at a required pressure. A valve for relieving pressure in the header is provided, together with electrical means for operating the same. This electrical means is connected with thermostatic devices that are appropriately distributed over the area to be protected. Thus when a dangerous condition is created in said area the thermostat device is affected to cause the electrical circuit to immediately open the pressure relieving valve in the header. As a result pressure in the pressure chamber of the deluge valve is relieved, and the latter opens to cause water to flow from the source of supply into the dry pipe system and out the open spray heads.

A somewhat more detailed object of the invention is the provision of a system of the character above noted in which means is provided in association with the pressure chamber and header for preventing water from flowing into the latter as an incident to opening of the deluge valve. This means preferably takes the form of a float valve that is closed as water enters the pressure chamber to cut off communication to the header.

Another detailed object of the invention is the provision of a pressure relieving valve, together with proper electrical operating instrumentalities to cause substantially instantaneous action on the part of the valve.

Various other more detailed objects and advantages of the invention will in part become apparent, and in part be hereinafter stated, as the description of the invention proceeds.

The invention, therefore, comprises a fire protective system of the dry pipe type in which the spray heads of the dry pipe water conduit system are maintained open, while the latter is connected to a source of water supply by a deluge valve. The deluge valve is maintained closed by the pressure of air in the pressure chamber, and this pressure may be relieved by an electrically operated valve that is connected in circuit with thermostatic devices distributed over the area to be protected.

For a full and more complete understanding of the invention reference may be had to the following description and accompanying drawing, wherein the figure is a diagrammatic showing of a fire protective system designed in accordance with the precepts of this invention.

Referring now to the drawing, wherein like reference characters denote corresponding parts,

the fire protective system of this invention is shown as generally comprising a dry pipe water conduit system referred to in its entirety by the reference character S, a deluge valve identified at V, a source of supply of water under pressure at W, and pressure control apparatus that is generally referred to by the reference character E,

The dry pipe water conduit system S is substantially the same as that illustrated and described in each of the copending applications of Lewis above identified. It may be briefly described as comprising a plurality of spray heads I0 which are maintained open, and which are connected by conduit sections designated A main feeder conduit for this system S is shown at I2, and this conduit I2 is connected to the deluge valve V. A deluge valve such as represented at V is now well-known in this art, being substantially of the type shown in United States Patents Nos. 1,569,326 and 1,765,840. The said copending applications of Lewis also disclose deluge or torrent valves of this same general type.

This valve V includes an outlet at l3 which is connected to the conduit |2 by a connection such as the bolted flange joint represented at Hi. The source of water supply depicted at W takes the form of a conduit l5, which may be connected as by the bolted flange connection shown at IS, with the valve inlet H. The upper end of the inlet terminates in a valve seat l8 that normally is closed by a gate valve I9 that is pivotally mounted as at 20 to the casing of the valve V.

A pressure chamber identified at 2| is defined by the casing of the valve V, and a gate valve 22 that has a greater expanse than the gate valve Hi. This gate valve 22 is pivotally mounted at 23 on the valve casing, and the valves l9 and 22 are connected by a link 24 that is pivotally connected at each end to each of the valves.

A pressure relieving outlet for the chamber 2| is depicted at 25, and certain parts of the control apparatus E may be connected thereto, as by the flanged connection represented at 26.

It is notable at this point that pressure of fluid in the chamber 2| normally affects the gate valve l9 to maintain the latter closed and shut off water from the source of supply W. However, if pressure in the chamber 2| should be relieved, pressure of water from the source of supply will force the gate valve I9 open, whereupon the water will flow through the valve V, out the outlet l3, and into the dry pipe system S.

An air tank in the form of a header is represented at 21, and the latter communicates with the pressure chamber 2|. However, there are times when it will be desirable to close off this communication, and for this purpose the float operated valve illustrated is interposed between the two.

This float operated valve is referred to in its entirety by the reference character 28, and comprises a casing 29 that is connected at its lower end to the flange connection 26. At the upper end the valve casing 29 terminates in an upwardly extending conduit 39 that is connected to a nipple 3| formed on the header 2'! by an appropriate coupling such as the flange connection shown at 32. At the point where the conduit 30 enters the chamber defined by the casing 29 it is formed with a conical valve seat 33. Disposed beneath the latter, in spaced relation, is a complemental valve member 34 that is carried by a stem 35 that is pivotally connected at 36 to an arm 31 that is pivotally mounted, as shown at 38, to the valve casing 29. The free end of the arm 31 carries a float 39.

It is evident that as the float rises under the influence of water entering the casing 29 it will raise the stem 35 (which is properly guided) and cause the valve member 34 to fit in the seat 33 and close the conduit 33 and communication to the header 2'1.

An air compressor is represented diagrammatically at 40. This compressor 40 is connected by the conduit shown at 4| with the header 21. The compressor 40 will be automatically operated, as occasion demands and in a manner now well-known in the various industrial arts, to keep the pressure of air in the: header 2'! and chamber 29 at a required predetermined point.

A pressure relieving valve for the header 2'! is represented at 42, and this valve is operated by electrical instrumentalities of the solenoid type, which are represented at 43.

Solenoid valves such as depicted at 42 and 43 are now well-known and available to the purchasing public. It is, therefore, deemed unnecessary to here describe in detail the mechanical elements and structure entering into this device. It suffices to say that when an electrical current is supplied to the solenoid at 43 the Valve 42 is opened to relieve the pressure of air in the header 21.

At the present time there is available to the public a thermostat known as a rate of rise and/or fixed temperature thermostat. Such a thermostat is illustrated and described in United States Patent No. 2,113,296, and may be briefly described by noting that it serves to complete an electrical circuit either when a certain predetermined temperature has been reached, or when there is a certain rate of rise of temperature over some range beneath the fixed temperature. A plurality of such thermostats are diagrammatically represented at 44, and will, of course, be properly distributed over the area to be protected. These thermostats 44 are included as a part of the electrical circuit represented by the lines 45 and 46, and the latter are connected to the solenoid 43 by the connection represented at 41.

While the operation of the above described apparatus is believed to be obvious, it may be briefly summarized as follows: When a condition about any of the thermostats 44 causes the latter to close the electrical circuits 4545, the solenoid 43 is affected to open the pressure relieving valve 42, and it is important to note that this action is substantially instantaneous. As pressure in the header 2'! is relieved, pressure in the chamber 2| is also relieved, whereupon the pressure of water from the supply W is efiective to open the gate valve IS. The water flows through the valve V, out the outlet l3, and into the conduits of the dry pipe system S, from whence it emerges through the open spray heads H].

It is important to note that any possibility of water flowing from the pressure chamber 2| of the valve V into the header 2'! is prevented by proper functioning of the float operated valve 28.

While a preferred specific embodiment of the invention is hereinbefore set forth it is to be clearly understood that the invention is not to be limited to the exact constructions illustrated and described, because various modifications of these details may be provided in putting the invention into practice within the purview of the appended claims.

I claim:

1. A fire protective system of the character described comprising a dry pipe water conduit system including an open spray head, a source of supply of water under pressure, a control valve interposed between said system and said source of supply and including a pressure chamber, a header communicating with said pressure chamher and adapted with said pressure chamber to receive air under pressure, means for maintaining the air in said chamber and header under a desired pressure, a pressure relieving valve carried by said header, a thermostat, and means, extraneous of said header and controlled by said thermostat, for instantly opening said pressure relieving valve.

2. A fire protective system of the character described, comprising a dry pipe conduit system including an open spray head, a supply of water under pressure, a control valve interposed between said supply of water and said dry pipe conduit system, and including a-pressure closing chamber and a pressure opening chamber, a supply of air under pressure in communication with said closing chamber, a pressure relieving valve in communication with said pressure closing chamber, a thermostat and instrumentalities under the control of said thermostat for instantaneously opening said pressure relieving valve to vent air from said pressure closing chamber.

LEROY M. LEWIS. 

